/Engine/Source/Runtime/Experimental/Chaos/Public/PhysicsProxy/GeometryCollectionPhysicsProxy.h
int32 CalculateEffectiveParticles ( const [FGeometryDynamicCollection](API\Runtime\Chaos\FGeometryDynamicCollection) & DynamicCollection, int32 NumTransform, [TBitArray](API\Runtime\Core\Containers\TBitArray)<> & EffectiveParticles ) const